Submission #693291

#	Time	Username	Problem	Language	Result	Execution time	Memory
693291		Tien_Noob	Two Antennas (JOI19_antennas)	C++17	13 / 100	81 ms	19596 KiB

antennas

//Make CSP great again
//Vengeance
#include <bits/stdc++.h>
#define TASK "TESTCODE"
using namespace std;
const int N = 2e5, oo = 2e9 + 1;
int n, q, h[N + 1], a[N + 1], b[N + 1];
int dp[2001][2001];
void maximize(int &a, int b)
{
    if (a < b)
    {
        a = b;
    }
}
void read()
{
    cin >> n;
    for (int i = 1; i <= n; ++ i)
    {
        cin >> h[i] >> a[i] >> b[i];
    }
}
void sub2()
{
    memset(dp, -1, sizeof(dp));
    for (int l = 1; l <= n; ++ l)
    {
        for (int r = l + a[l]; r <= min(n, l + b[l]); ++ r)
        {
            if (r - b[r] <= l && l <= r - a[r])
            {
                dp[l][r] = abs(h[l] - h[r]);
            }
        }
    }
    for (int lens = 2; lens <= n; ++ lens)
    {
        for (int l = 1; l + lens - 1 <= n; ++ l)
        {
            int r = l + lens - 1;
            maximize(dp[l][r], dp[l][r - 1]);
            maximize(dp[l][r], dp[l + 1][r]);
        }
    }
    cin >> q;
    while(q--)
    {
        int l, r;
        cin >> l >> r;
        cout << (dp[l][r] == oo ? -1 : dp[l][r]) << '\n';
    }
}
void solve()
{
    if (n <= 2000)
    {
        sub2();
        return ;
    }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (fopen(TASK".INP", "r"))
    {
        freopen(TASK".INP", "r", stdin);
        //freopen(TASK".OUT", "w", stdout);
    }
    int t = 1;
    bool typetest = false;
    if (typetest)
    {
        cin >> t;
    }
    for (int __ = 1; __ <= t; ++ __)
    {
        //cout << "Case " << __ << ": ";
        read();
        solve();
    }
}

Compilation message (stderr)

antennas.cpp: In function 'int main()':
antennas.cpp:68:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |         freopen(TASK".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 2 / 2
• Subtask 2: 11 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 65